The family of natural products known as the schweinfurthins includes four compounds isolated from the African plant Macaranga schweinfurthii Pax (see Beutler, J. A. et al., J. Nat. Prod. 1998, 61, 1509-1512; and Beutler, J. A., et al., Nat. Prod. Lett. 2000, 14, 349-404). Schweinfurthins A, B, and D display significant activity in the NCI's 60-cell line anticancer assay with mean GI50's<1 μM. Their biological activity has attracted interest because some CNS, renal, and breast cancer cell lines are among the types most sensitive to these compounds. Inspection of the spectrum of activity shows no correlation with any currently used agents and suggests that these compounds may be acting at a previously unrecognized target or through a novel mechanism.
The further development of schweinfurthins as cancer therapeutics would be accelerated by elucidating their mechanism of action. Currently there is a need for schweinfurthin analogs that can be used as probes for elucidating the mechanism of action of these unique anti-cancer agents.